牡丹花衰老过程中的生理生化变化

牡丹花从开放到凋谢期间，花瓣和叶片的可溶性蛋白质含量前期增加，后期下降，细胞质膜透性、丙二醛（MDA）、超氧阴离子（O2^-)产生量随花瓣的衰老逐渐增加，超氧化歧化酶（SOD）活性逐渐降低，花瓣的变幅大于叶片，这与形态观察到的花瓣的衰老明显于叶片的现象一致，相关分析表明花瓣可溶性蛋白质含量、质膜透性、MDA含量、SOD酶活性和超氧阴离子自由基之间呈显著相关关系，而叶片则不然，衰老末期可溶性蛋白质含量与游离氮基酸总量之间没有相关性，这与养分耗尽有关。因为认为牡丹花衰老是多因素综合调控而导致细胞编程性死亡的结果。

THE CHANGES OF PHYSIOLOGY AND BIOCHEMISTRY IN PEONY DURING SENESCENCE

From florescence to senescence of tree peony, soluble protein content for both petals and leaves increased at prophase, and then began to decrease at anaphase. Membrane permeability, MDA content and O2- production rates increasingly were enhanced, but SOD activity gradually reduced with the fading of petals. Petals changed more obviously than leaves, which was correspondent with morphologic observation. Relative analysis showed that in petals, there is obvious correlation among soluble protein content, membrane permeability, MDA content, SOD activity and O2- production rates. However in leaves there is no correlevticn between soluble protein content concentration of free amino acid, which is possibly related to nutrient exhausting. Therefore, senescence for tree peony is caused by programmed cell death controlled by the universal action of many factors.